Cover opening and closing mechanism and electronic apparatus

ABSTRACT

An opening and closing mechanism for a cover is openable and closable with respect to a body. The mechanism includes a link structure supported at the body rotatably within a range of a first predetermined angle from a closed state of the cover, and supporting the cover rotatably within a range of a second predetermined angle. The link structure is rotated integrally with the cover when being rotated within the range of the first predetermined range. The cover is solely rotated within the range of the second predetermined angle when the link structure has been rotated by the first predetermined angle from the closed state of the cover.

BACKGROUND

1. Technical Field

The present invention relates to an opening and closing mechanism for a cover openable and closable with respect to a body, and an electronic apparatus provided with the opening and closing mechanism for the cover.

2. Related Art

An electronic apparatus usually has an opening at an upper surface of a housing to facilitate maintenance of the inside of the housing. Such an opening is necessary to be widely provided for facilitating the maintenance, but otherwise closed to prevent dust and the like from entering. Owing to this, the opening is covered with a cover that is rotated within a range of a large angle to open and close the opening.

An opening and closing mechanism for the cover may be a mechanism in which shafts protrude at both sides of one end of the cover while holes are formed both sides of one end of the opening, and the shafts are inserted to the holes to support the cover rotatably about the shafts. Alternatively, the opening and closing mechanism may be a mechanism in which one piece of a hinge is fixed at the one end of the cover with a screw or the like, while the other piece of the hinge is fixed at the one end of the opening with a screw or the like, and the cover is rotatably supported by the hinge (see JP-A-2005-41213).

However, with the opening and closing mechanism using the shafts and the holes, or that using the hinge, if a user releases his/her hand from the cover in the middle of opening the cover, the cover may be rapidly closed due to its weight and damaged. In addition, an interference range of the cover and the housing may increase due to the degree of opening of the cover, the thickness of the cover, and the like. Therefore, a relatively-large gap is required between the cover and the housing. Due to this, dust and the like likely enters the gap, and the housing needs to be designed such that the inside of the housing is not exposed through the gap.

To address those problems, a concealed hinge may be used. The concealed hinge has one end fixed to the back surface of the cover with a screw or the like, and the other end supported at the inner surface of the housing rotatably about a shaft and biased with a torsion coil spring. However, the opening is necessary to be rotated within a range of a large angle to open and close the opening, the concealed hinge may increase in size, and hence, the rotation space for the concealed hinge must be widely secured in the housing. Accordingly, it is difficult to downsize the electronic apparatus.

SUMMARY

An advantage of some aspects of the invention is that a small opening and closing mechanism for a cover with a sufficient opening and closing angle, and an electronic apparatus provided with the opening and closing mechanism for the cover are provided.

An opening and closing mechanism for a cover according to an aspect of the invention is openable and closable with respect to a body. The mechanism includes a link structure supported at the body rotatably within a range of a first predetermined angle from a closed state of the cover, and supporting the cover rotatably within a range of a second predetermined angle. The link structure is rotated integrally with the cover when being rotated within the range of the first predetermined range. The cover is solely rotated within the range of the second predetermined angle when the link structure has been rotated by the first predetermined angle from the closed state of the cover.

An opening and closing mechanism for a cover according to another aspect of the invention is openable and closable with respect to a body. The mechanism includes a link having at one end a first hinge supported at the body side, and having at the other end a second hinge supported at the cover side. When the cover is open, the cover is integrally rotated with the link about the first hinge by a first predetermined angle, then the cover is solely rotated about the second hinge by a second predetermined angle, and the cover is maintained in an open state. When the cover is closed, the cover is solely rotated about the second hinge by the second predetermined angle, then the cover is integrally rotated with the link about the first hinge by the first predetermined angle, and the cover is maintained in a closed state. With this configuration, since the cover is opened and closed by the link structure having the two supporting points, the cover can be widely opened without interfering with the body even if the link structure decreases particularly in height. In addition, since the link structure is downsized, it would not interfere with the main components in the body, so that the main components may be more desirably arranged.

Preferably, the link may include a biasing unit for biasing the cover in its opening direction by a moment substantially equivalent to a moment caused by a weight of the cover when the cover is rotated in the opening direction about the first hinge by the first predetermined angle. With this configuration, the cover can be maintained in the opening state when the cover has reached the first predetermined angle, and also, even when a user releases his/her hand from the cover in the middle of opening the cover toward the first predetermined angle, the cover may be closed slowly. Preferably, the link and the cover may have rotation restrictors that restrict the rotation of the cover and the link when the cover and the link have been rotated by the first predetermined angle, and rotation restrictors that restrict the rotation of the cover when the cover has been rotated by the second predetermined angle. With this configuration, the cover can be always open at accurate angles. Preferably, the first and second hinges may be disposed not to protrude from the body when the cover is in the closed state. With this configuration, the entire body can be designed compactly.

An electronic apparatus according to still another aspect of the invention includes the above-mentioned opening and closing mechanism for the cover. Preferably, the electronic apparatus may be a recording device that performs a recording operation on a recording medium. With this configuration, there can be provided the electronic apparatus and the recording medium which may attain the above-described advantages.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.

FIG. 1 is a perspective view showing the diagonally front side of the exterior of an ink jet printer which is an example of a recording device according to an embodiment of the invention.

FIG. 2 is a perspective view showing the diagonally rear side of the exterior of the printer shown in FIG. 1.

FIG. 3 is a perspective view generally showing the interior of the printer shown in FIG. 1.

FIG. 4 is a lateral cross section generally showing the interior of the printer shown in FIG. 1.

FIG. 5 is a perspective view showing the front side of the printer shown in FIG. 1 in a state where a printer cover is open.

FIG. 6 is a first lateral cross section showing transition from a state where the printer cover shown in FIG. 5 is closed to a state where the printer cover is open.

FIG. 7 is a second lateral cross section showing the transition from the state where the printer cover shown in FIG. 5 is closed to a state where the printer cover is open.

FIG. 8 is a third lateral cross section showing the transition from the state where the printer cover shown in FIG. 5 is closed to a state where the printer cover is open.

FIG. 9 is an illustration showing the action of a torsion coil spring of the printer cover shown in FIG. 5.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

An exemplary embodiment of the invention will be described below with reference to the attached drawings. Note that the below-described embodiment does not restrict the invention pertaining to claims, and the solution of the invention may not necessitate all of the combinations of features mentioned in the embodiment.

FIGS. 1 and 2 are perspective views showing the diagonally front and rear sides of the exterior of an ink jet printer which is an example of a recording device according to an embodiment of the invention. FIG. 3 is a perspective view generally showing the interior thereof. FIG. 4 is a lateral cross section generally showing the interior thereof. This ink jet printer 100 can perform a recording operation on a cut-sheet (hereinafter, referred to as “sheet”, corresponding to a recording medium) with ink. A variety of sizes is available for such a sheet, such as Japanese photo paper sizes including L, 2L, and postcard; and Japanese Industrial Standards (JIS) A series sizes including A4, slightly larger than A3, and A2.

As shown in FIGS. 1 and 2, the ink jet printer 100 is entirely covered with a housing (body) 101 being substantially a rectangular parallelepiped. An operation unit 110 is disposed at the upper right side of the housing 101 (shown in FIG. 1), and a cartridge accommodating unit 120 is disposed at the upper left side (shown in FIG. 1) thereof. A first rear sheet feeding unit 130 is disposed at the upper rear side (shown in FIG. 1). A second rear sheet feeding unit 140 is disposed at the rear side (shown in FIG. 2). A sheet discharging unit 150 and a front sheet feeding unit 160 are disposed at the front side (shown in FIG. 1). A waste ink recovering unit 170 is disposed at the front right side (shown in FIG. 1). Provided inside the ink jet printer 100 are a controlling unit 190 (shown in FIGS. 2 and 4), and a sheet transporting unit 180 and a recording unit 200 (shown in FIGS. 3 and 4).

In addition, a rectangular opening 102 is formed at the upper surface of the housing 101 between the first rear sheet feeding unit 130, and the operation unit 110 and the cartridge accommodating unit 120. The opening 102 is covered with a printer cover (cover) 210 which is a substantially rectangular plate. The printer cover 210 is mounted rotatably in the directions of the illustrated double-headed arrow a by a cover opening and closing mechanism 211 (see FIG. 5), a characteristic portion of the invention. A user can easily perform maintenance for the internal mechanisms, such as the sheet transporting unit 180 and the recording unit 200, through the opening 102 by lifting the printer cover 210 and uncovering the opening 102. The cover opening and closing mechanism 211 will be described later in detail.

As shown in FIGS. 1 and 2, the operation unit 110 includes a substantially rectangular operation panel 111. A liquid crystal panel 112 is disposed substantially at the center of the operation panel 111 and displays an operation state and the like. Buttons 113 are disposed on both sides of the liquid crystal panel 112, for a power system that turns power ON/OFF, an operation system that performs positioning of the leading edge of a sheet or flushing of ink, and for a processing system that performs image processing. Since the user can operate the buttons 113 while checking the liquid crystal panel 112, it is possible to prevent an erroneous operation.

As shown in FIGS. 1 and 2, the cartridge accommodating unit 120 accommodates ink cartridges 121 (shown in FIGS. 3 and 4) in a detachably attached manner. The ink cartridges 121 store ink of print colors (nine print colors in the embodiment). The cartridge accommodating unit 120 is covered with a cartridge cover 122 that is L-shaped in cross section. The cartridge cover 122 is mounted rotatably in the directions of the illustrated double-headed arrow b around a rotary shaft provided at its rear end. The user can easily replace the ink cartridges 121 by lifting the cartridge cover 122 and uncovering the cartridge accommodating unit 120, thereby improving working efficiency.

The first rear sheet feeding unit 130 is designated as automatic sheet feed (ASF). As shown in FIGS. 1 and 2, the first rear sheet feeding unit 130 includes a first sheet support 132 having a four-stage structure and involving a function of opening and closing a rectangular first sheet feeding opening 131 extended upward and a function of supporting one or a plurality of sheets to be fed. The first sheet support 132 is mounted rotatably in the directions of the illustrated double-headed arrow c around a rotary shaft provided at its rear end. The sheets to be fed by the first rear sheet feeding unit 130 are relatively thin (for example, plain paper or photo paper of about 0.08 to 0.27 mm in thickness).

Before the use of the ink jet printer 100, the user may complete setting of the first sheet support 132 by placing a finger at a hole 132 a, which is provided at the front center of the first sheet support 132, lifting the first sheet support 132, and drawing the multistage portion. Accordingly, the first sheet support 132 need not be stored or maintained unlike a removable sheet support. In addition, the first sheet support 132 has the multistage structure, whereby it may reliably support a variety of sizes of sheets to be fed. After the use of the ink jet printer 100, the first sheet feeding opening 131 can be closed by pushing the multistage portion of the first sheet support 132. Accordingly, it is possible to prevent dust from entering the printer body, and to store the first sheet support 132 compactly.

The second rear sheet feeding unit 140 is designated as manual sheet feed. As shown in FIG. 2, the second rear sheet feeding unit 140 includes a second sheet support 142 having a two-stage structure and involving a function of opening and closing a rectangular second sheet feeding opening 141 extended rearward and a function of supporting one sheet to be fed. The second sheet support 142 is mounted rotatably in the directions of the illustrated double-headed arrow d around a rotary shaft provided at its lower end. The sheet to be fed by the second rear sheet feeding unit 140 is a sheet having a thickness that cannot be fed at a transportation angle in the first rear sheet feeding unit 130 (for example, drawing paper or special paper of about 0.29 to 0.48 mm in thickness). Since the first rear sheet feeding unit 130 is designated as the automatic sheet feed (ASF), it picks up a sheet by a sheet feeding roller 82. If paper dust adheres to the sheet feeding roller 82, the sheet feeding roller 82 may slip off a sheet and cause misfeed of the sheet. Therefore, sheets tending to produce paper dust (such as velvet Fine Art Paper of about 0.48 mm in thickness, and Ultra Smooth Fine Art Paper of about 0.46 mm in thickness, both produced by Seiko Epson Corporation) are also need to be manually fed by the second rear sheet feeding unit 140.

Before the use of the ink jet printer 100, the user may complete setting of the second sheet support 142 by placing a finger at an upper portion of the second sheet support 142, bringing down the second sheet support 142, and drawing the multistage portion. Accordingly, the second sheet support 142 need not be stored or maintained unlike a removable sheet support. In addition, the second sheet support 142 has the multistage structure, whereby it may reliably support a variety of sizes of sheets to be fed. After the use of the ink jet printer 100, the second sheet feeding opening 141 can be closed by pushing the multistage portion of the second sheet support 142. Accordingly, it is possible to prevent dust from entering the printer body, and to store the second sheet support 142 compactly.

As shown in FIG. 1, the sheet discharging unit 150 includes a stacker 152 having a two-stage structure. The stacker 152 includes a first stacker portion 51 and a second stacker portion 52 (shown in FIG. 3) involving a function of opening and closing a rectangular sheet discharging opening 151 extended forward and a function of stacking one or a plurality of sheets to be discharged. The first stacker portion 51 is mounted rotatably in the directions of the illustrated double-headed arrow e around a rotary shaft provided at the front end of the second stacker portion 52. The second stacker portion 52 is mounted so as to protrude and be accommodated by moving in parallel and obliquely vertically with respect to the sheet discharging opening 151.

Before the use of the ink jet printer 100, the user may, complete setting of the stacker 152 by placing a finger at the upper portion of the first stacker portion 51, rotating the first stacker portion 51 forward, uncovering the sheet discharging opening 151, pinching the front end of the first stacker portion 51 with fingers, drawing the first stacker portion 51, moving the second stacker portion 52 in parallel and obliquely upward to protrude. Accordingly, the stacker 152 need not be stored or maintained unlike a removable stacker. In addition, the stacker 152 has the multistage structure, whereby it may reliably stack a variety of sizes of sheets to be discharged. Also, the recorded sheets are always discharged from the front side, whereby the user may easily take out the sheets. After the use of the ink jet printer 100, the sheet discharging opening 151 can be closed by manually pushing the first end of the first stacker portion 51, moving the second stacker portion 52 in parallel and obliquely downward to be accommodated, placing a hand at the first stacker portion 51, and rotating the first stacker portion 51 rearward. Accordingly, it is possible to prevent dust from entering the printer body, and to store the stacker 152 compactly.

The front sheet feeding unit 160 is designated as manual sheet feed. As shown in FIG. 3, the front sheet feeding unit 160 includes a sheet feeding tray 161 disposed above the stacker 152 in the sheet discharging opening 151. The sheet feeding tray 161 is provided horizontally movably with respect to the sheet discharging opening 151. Sheets to be fed by the front sheet feeding unit 160 are sheets that are relatively thick and cannot be bent when transporting them (for example, matte board paper of about 1.2 mm in thickness).

Before the use of the ink jet printer 100, when the user lightly pushes the first end of the sheet feeding tray 161, a stopper of the sheet feeding tray 161 is disengaged and the sheet feeding tray 161 protrudes from the sheet discharging opening 151. After the use of the ink jet printer 100, when the user lightly pushes the first end of the sheet feeding tray 161, the stopper of the sheet feeding tray 161 is engaged and the sheet feeding tray 161 is accommodated in the sheet discharging opening 151. Therefore, the sheet feeding tray 161 may efficiently save the space to be disposed.

As shown in FIGS. 1 to 3, the waste ink recovering unit 170 accommodates a waste ink tank 171 in a detachably attached manner. The waste ink tank 171 which stores waste ink and the like. The waste ink tank 171 stores the waste ink and the like that is exhausted when a recording head 202 is cleaned or the ink cartridges are replaced. When the waste ink tank 171 is filled with the waste ink and the like, the user draws out the waste ink tank 171 and inserts another waste ink tank 171, thereby facilitating the replacement of the waste ink tank 171.

As shown in FIGS. 3 and 4, the sheet transporting unit 180 extends from the first rear sheet feeding unit 130 and the second rear sheet feeding unit 140 to the sheet discharging unit 150. The sheet transporting unit 180 includes an automatic sheet feeding mechanism 181, a transporting mechanism 182, and a sheet discharging mechanism 183. As shown in FIG. 4, the automatic sheet feeding mechanism 181 includes a hopper 81, a sheet feeding roller 82, a retard roller 83, and a sheet returning lever 84. The hopper 81 lifts up sheets supported by the first sheet support 132 to feed them. The sheet feeding roller 82 takes out the sheets lifted by the hopper 81. The retard roller 83 separates one of the sheets double-fed by the sheet feeding roller 82. The sheet returning lever 84 returns the residual sheets separated by the retard roller 83 to the hopper 81.

The hopper 81 is platy to allow sheets to be placed thereon, and is disposed substantially in parallel to a rear wall. The lower end of the hopper 81 is positioned near the sheet feeding roller 82, and the upper end thereof is positioned near the top portion of the rear wall. A compression spring (not shown) has one end attached to the rear wall and the other end attached to the back surface at the lower end of the hopper 81. The hopper 81 is disposed so that the lower end of the hopper 81 is turnable around its upper end due to expansion and compression of the compression spring.

The sheet feeding roller 82 has a D shape since a portion of its cross section is cut out, and is disposed near the lower end of the hopper 81. The sheet feeding roller 82 rotates intermittently to frictionally feed the sheets that are lifted by the hopper 81. The retard roller 83 is disposed to abut on or be separated from the sheet feeding roller 82, thereby frictionally separating only the topmost one of the sheets when the sheets are double-fed by the sheet feeding roller 82. The sheet returning lever 84 is formed like a pawl and is disposed near the sheet feeding roller 82. The residual sheets that have been separated by the retard roller 83 are caught by the pawl to return them to the hopper 81.

As shown in FIG. 4, the transporting mechanism 182 includes a sheet feeding roller 85 and a driven roller 86, which transport sheets in a sub-scanning direction in synchronism with a recording operation. The sheet feeding roller 85 is disposed upstream of a platen 203 in the sheet transportation direction. The sheet feeding roller 85 and the driven roller 86 pinch a sheet that is fed by the sheet feeding roller 82 to send the sheet to the platen 203.

As shown in FIG. 4, the sheet discharging mechanism 183 includes a sheet discharging roller 87, a first serrated roller 88 a, and a second serrated roller 88 b. The first serrated roller 88 a is disposed downstream of the platen 203 in the sheet transportation direction. The second serrated roller 88 b and the sheet discharging roller 87 are disposed downstream of the first serrated roller 88a in the sheet transportation direction to oppose each other. The sheet that has passed the platen 203 is discharged by the first serrated roller 88 a and then, and pinched by the second serrated roller 88 b and the sheet discharging roller 87 to be discharged onto the stacker 152. The first serrated roller 88 a and the second serrated roller 88 b are held by the same holding member (not shown).

As shown in FIG. 4, the controlling unit 190 includes a main substrate 191 that constitutes a printer controller. Though not shown, the main substrate 191 has controlling elements and storage elements, such as a CPU, ROM, RAM, or ASIC, and other circuit elements. The controlling unit 190 controls the sheet transporting unit 180, the recording unit 200, and the like, of a print engine.

As shown in FIG. 4, the recording unit 200 includes a carriage 201 that moves in a main-scanning direction in synchronism with a recording operation, the recording head 202 that discharges ink in synchronism with the recording operation, and the platen 203 that holds the sheet in a flat state during the recording. As shown in FIG. 3, the carriage 201 passes through a carriage guide shaft 204 above the platen 203 and is connected to a carriage belt 205. When the carriage belt 205 is operated by a carriage motor (not shown), the carriage 201 is moved by the movement of the carriage belt 205 and is guided along the carriage guide shaft 204, so that it reciprocates.

As shown in FIG. 4, the recording head 202 is mounted to the carriage 201 so that a predetermined interval is provided between the recording head 202 and the platen 203. The recording head 202 can discharge ink of two types of black, such as photo-black and matte black, and ink of seven colors, yellow, cyan, light cyan, magenta, light magenta, gray, and red. In other words, the recording head 202 includes a nozzle plate having a pressure generating chamber and a nozzle connected to the pressure generating chamber. An ink droplet having a controlled size is discharged towards the sheet from the nozzle by storing the ink in the pressure generating chamber and applying a predetermined pressure thereto. The platen 203 is disposed between the sheet feeding roller 85 and the sheet discharging roller 87 so as to oppose the recording head 202, and supports a surface of the sheet that is being transported. Next, the cover opening and closing mechanism 211, a characteristic portion of the invention, will be described in more detail with reference to the drawings.

FIG. 5 is a perspective view showing the front side of the printer in a state where the printer cover 210 is open. FIGS. 6 to 8 are lateral cross sections each showing transition from a state where the printer cover 210 is closed to a state where it is open. As shown in FIG. 5, the cover opening and closing mechanism 211 is disposed at either side of the first rear sheet feeding unit 130. As shown in FIG. 6, one end of the cover opening and closing mechanism 211 is rotatably attached at the inner side of the upper surface of the housing 101, while the other end thereof is rotatably attached at the back surface at the rear end of the printer cover 210.

Each cover opening and closing mechanism 211 includes a substantially L-shaped link (link structure) 212 and a torsion coil spring (biasing unit) 213. The link 212 has holes (link structure, first and second hinges) 212 a and 212 b at its both ends. A shaft (link structure, first hinge) 214 a is provided at the inner side of the upper surface of the housing 101, inserted through the hole (link structure, first hinge) 212 a provided at one end of the link 212, and rotatably supported by the hole 212 a. A shaft (link structure, second hinge) 214 b is provided at the back surface at the rear end of the printer cover 210, inserted through the hole (link structure, second hinge) 212 b provided at the other end of the link 212, and rotatably supported by the hole 212 b.

Additionally, the link 212 has a substantially triangular protruded portion (rotation restrictor) 212 c provided at the outer side of the angular part of the L-shaped portion. The torsion coil spring 213 is inserted to the shaft 214 a provided at the inner side of the upper surface of the housing 101. One end of the torsion coil spring 213 is engaged at a protrusion 213 a provided at the inner side of the upper surface of the housing 101, while the other end thereof is engaged at the protruded portion 212 c provided at the link 212.

With this configuration, the printer cover 210 forms a double-hinge mechanism that is rotatable about the two shafts 214 a and 214 b. In particular, the link 212 is supported rotatably within a range of a first predetermined angle (about 90 degrees) θ1 defined between the printer cover 210 in a closed state shown in FIG. 6 and that in a half-open state shown in FIG. 7. Besides, the printer cover 210 is supported rotatably within a range of a second predetermined angle (about 45 degrees) θ2 defined between the printer cover 210 in the half-open state shown in FIG. 7 and that in a full-open state shown in FIG. 8.

Within the first predetermined angle θ1, a rib (rotation restrictor) 210 a provided at the back surface at the rear end of the printer cover 210 abuts on the other end portion (rotation restrictor) 212 d of the link 212 to restrict rotation of the printer cover 210. When the printer cover 210 has been rotated by the first predetermined angle θ1 from the closed state, namely, to the half-open state, the protruded portion (rotation restrictor) 212 c of the link 212 abuts on a wall (rotation restrictor) 215 a provided at the housing 101 to restrict the rotation of the link 212. In addition, when the printer cover 210 has been rotated by the second predetermined angle θ2 from the half-open state, namely, to the full-open state, an edge portion (rotation restrictor) 210 b provided at a lower end of the printer cover 210 abuts on a center portion (rotation restrictor) 212 e of the link 212 to restrict the rotation of the printer cover 210. As described above, the printer cover 210 is integrally rotated with the link 212 in the range between the closed state shown in FIG. 6 and the half-open state shown in FIG. 7. Then, the printer cover 210 is solely rotated in the range between the half-open state shown in FIG. 7 and the full-open state shown in FIG. 8.

Note that the printer cover 210 is rotatably supported by the link 212 not just in the range between the half-open state shown in FIG. 7 and the full-open state shown in FIG. 8. The printer cover 210 may-be rotated with respect to the link 212 within the range of the second predetermined angle 02. Therefore, when the printer cover 210 is lifted from the closed state shown in FIG. 6, the printer cover 210 would not be integrally rotated with the link 212, and the printer cover 210 is solely rotated to the second predetermined angle θ2. To avoid this, the torsion coil spring 213 is provided.

FIG. 9 is an illustration showing the action of the torsion coil spring 213. The torsion coil spring 213 is attached to apply a biasing force in the opening direction of the printer cover 210. The biasing force F is determined in relation to a weight W of the printer cover 210 including the link 212. Specifically, a moment Mf acting on the link 212 including the printer cover 210 caused by the biasing force F of the torsion coil spring 213 is expressed by a product of the biasing force F of the torsion coil spring 213 and a distance Df from a central point C of the shaft 214 a inserted to the hole 212 a at the one end of the link 212 to an engagement point E at which the other end of the torsion coil spring 213 is engaged with respect to the protruded portion 212 c of the link 212, i.e., Mf=F×Df.

Meanwhile, a moment Mw acting on the link 212 including the printer cover 210 caused by the weight W of the printer cover 210 including the link 212-is expressed by a product of the weight W of the printer covert 210 including the link 212 and a distance Dw from the central point C of the shaft 214 a inserted to the hole 212 a at the one end of the link 212 to the center of gravity G of the printer cover 210 including the link 212, i.e., Mw=W×Dw.

Since the distance Df is constant, the above-expressed moment Mf is also constant. However, since the distance Dw is linearly varied in the range between the closed state and the half-open state of the printer cover 210, the moment Mw is also linearly varied. Therefore, The biasing force F of the torsion coil spring 213 is determined so that the minimum moment Mw, namely, the moment Mw when the printer cover 210 is in the half-open state, is substantially equivalent with the inversely acting moment Mf.

Accordingly, when the user opens the printer cover 210, the moment Mf in the opening direction is applied, and hence the user can easily lift up and rotate the printer cover 210 with the link 212 until the protruded portion 212 c of the link 212 abuts on the wall 215 a of the housing 101 and thus the rotation of the printer cover 210 with the link 212 is restricted. When the printer cover 210 becomes the half-open state, even if the user releases his/her hand from the printer cover 210, the printer cover 210 is maintained in the half-open state since the moment Mf and the moment Mw substantially equivalently act in the opening and closing directions, respectively.

When the user pushes the printer cover 210 rearward, the protruded portion 212 c of the link 212 abuts on the wall 215 a provided at the housing 101 and thus the rotation of the link 212 is restricted. Accordingly, the printer cover 210 may be solely moved rearward until the edge portion 210 b abuts on the center portion 212 e of the link 212 and thus the rotation of the printer cover 210 is restricted. When the printer cover 210 becomes the full-open state, even if the user releases his/her hand from the printer cover 210, the printer cover 210 is maintained in the full-open state since the moment Mf and the moment Mw substantially equivalently act in the opening direction, respectively.

On the other hand, when the user closes the printer cover 210, he/she pulls the printer cover 210 forward to be the half-open state until the rib 210 a of the printer cover 210 abuts on the other end portion 212 d of the link 212 and thus the rotation of the printer cover 210 is restricted. Then, the printer cover 210 is further pushed down. At this time, the printer cover 210 can be easily closed since the moment Mw is applied in the closing direction. When the printer cover 210 becomes the closed state, even if the user releases his/her hand from the printer cover 210, the printer cover 210 is maintained in the closed state since the moment Mw, which is larger than the moment Mf, is applied in the closing direction.

As described above, the cover opening and closing mechanism 211 according to the embodiment includes the link 212 having the one end supported at the housing 101 side provided with the hole 212 a and the shaft 214 a, and the other end supported at the printer cover 210 side provided with the hole 212 b and the shaft 214 b. When the printer cover 210 is open, the printer cover 210 and the link 212 are integrally rotated about the hole 212 a and the shaft 214 a by the first predetermined angle θ1, then the printer cover 210 is solely rotated about the hole 212 b and the shaft 214 b by the second predetermined angle θ2, and the printer cover 210 is maintained in the open state. On the other hand, when the printer cover 210 is closed, the printer cover 210 is solely rotated about the hole 212 b and the shaft 214 b by the second predetermined angle θ2, then the printer cover 210 and the link 212 are integrally rotated about the hole 212 a and the shaft 214 a by the first predetermined angle θ1, and the printer cover 210 is maintained in the closed state. Accordingly, since the printer cover 210 is opened and closed by the link structure including the elements 212, 212 a, 214 a, 212 b and 214 b, the printer cover 210 can be widely opened without interfering with the housing 101 even if the link structure including the elements 212, 212 a, 214 a, 212 b and 214 b decrease particularly in height. In addition, since the link structure including the elements 212, 212 a, 214 a, 212 b and 214 b may be downsized, those would not interfere with the main components in the ink jet printer 100, so that the main components may be more desirably arranged.

Further, since the link 212 includes the torsion coil spring 213 for biasing the link 212 including the printer cover 210 in the opening direction by the moment Mf that is substantially equivalent with the moment Mw caused by the weight W of the printer cover 210 including the link 212 when the link 212 is rotated about the hole 212 a and the shaft 214 a by the first predetermined angle θ1. Accordingly, the printer cover 210 can be maintained in the opening state at the first predetermined angle θ1, and also, even when the user releases his/her hand from the printer cover 210 in the middle of opening the printer cover 210 toward the first predetermined angle θ1, the printer cover 210 may be closed slowly.

Further, the link 212 includes the other end portion 212 d that restricts the rotation of the printer cover 210 when it is rotated by the first predetermined angle θ1, and the protruded portion 212 c that restricts the rotation of the printer cover 210 when it has been rotated by the first predetermined angle θ1. Besides, the printer cover 210 includes the rib 210 a that restricts the sole rotation of the printer cover 210 when it is rotated by the first predetermined angle θ1, and the edge portion 210 b that restricts the rotation of the printer cover 210 when it has been rotated by the second predetermined angle θ2. Accordingly, the printer cover 210 can be always open at accurate angles. Further, the link 212 is disposed in the housing 101, and hence, the holes 212 a and 212 b, and the shafts 214 a and 214 b are disposed to be invisible from the outside and not to protrude from the housing 101. Accordingly, the entire ink jet printer 100 can be designed compactly.

While the ink jet printer is described above as an example of a recording device provided with the cover opening and closing mechanism, the recording device may be a facsimile, a copier, or the like, as long as it is provided with the cover opening and closing mechanism. The cover opening and closing mechanism may not be applied to the recording device, and may be applied to any kind of electric apparatuses. 

1. An opening and closing mechanism for a cover openable and closable with respect to a body, the mechanism comprising: a link structure supported at the body rotatably within a range of a first predetermined angle from a closed state of the cover, and supporting the cover rotatably within a range of a second predetermined angle, wherein the link structure is rotated integrally with the cover when being rotated within the range of the, first predetermined range, and the cover is solely rotated within the range of the second predetermined angle when the link structure has been rotated by the first predetermined angle from the closed state of the cover.
 2. An opening and closing mechanism for a cover openable and closable with respect to a body, the mechanism comprising: a link having at one end a first hinge supported at the body side, and having at the other end a second hinge supported at the cover side, wherein when the cover is open, the cover is integrally rotated with the link about the first hinge by a first predetermined angle, then the cover is solely rotated about the second hinge by a second predetermined angle, and the cover is maintained in an open state, and when the cover is closed, the cover is solely rotated about the second hinge by the second predetermined angle, then the cover is integrally rotated with the link about the first hinge by the first predetermined angle, and the cover is maintained in a closed state.
 3. The opening and closing mechanism for the cover according to claim 2, wherein the link includes a biasing unit for biasing the cover in its opening direction by a moment substantially equivalent to a moment caused by a weight of the cover when the cover is rotated in the opening direction about the first hinge by the first predetermined angle.
 4. The opening and closing mechanism for the cover according to claim 2, wherein the link and the cover have rotation restrictors that restrict the rotation of the cover and the link when the cover and the link have been rotated by the first predetermined angle, and the rotation of the cover when the cover has been rotated by the second predetermined angle.
 5. The opening and closing mechanism for the cover according to claim 2, wherein the first and second hinges are disposed not to protrude from the body when the cover is in the closed state.
 6. An electronic apparatus comprising the opening and closing mechanism for the cover according to claim
 1. 7. The electronic apparatus according to claim 6, wherein the electronic apparatus is a recording device that performs a recording operation on a recording medium. 